STRIDE-10 Results Support Merck’s 21-Valent Pneumococcal Conjugate Vaccine

Positive findings were announced from a phase 3 trial comparing Merck’s investigational 21-valent pneumococcal conjugate vaccine, V116, to pneumococcal 23-valent polyvalent vaccine (PPSV23) in pneumococcal vaccine-naïve adults.

The double-blind, active comparator-controlled phase 3 STRIDE-10 trial (ClinicalTrials.gov Identifier: NCT05569954) evaluated the safety and immunogenicity of V116 in pneumococcal vaccine-naïve adults 50 years of age and older (N=1484). Study participants were randomly assigned to receive a single dose of either V116 or PPSV23. 

The primary outcome measures included serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs) at day 30 post vaccination and the percentage of participants with at least a 4-fold rise from baseline in serotype-specific OPAs. 

Results showed V116 elicited noninferior immune responses compared with PPSV23 for the 12 serotypes common to both vaccines. Additionally, superior immune responses were observed for the 9 serotypes included in V116 but not in PPSV23, and for 8 of 9 serotypes to V116 compared with PPSV23, as measured by the proportions of participants with at least a 4-fold rise in immune responses. 

“Even with the availability of current pneumococcal conjugate vaccines for adults, gaps in serotype coverage for invasive pneumococcal disease persist,” said Dr Eliav Barr, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories. “These data add to the evidence supporting the potential for V116 to become an important new preventive option for adults, with results showing V116 elicited immune responses to the serotypes responsible for the majority of adult invasive pneumococcal disease.”

V116 is currently under Priority Review by the Food and Drug Administration (FDA) for the prevention of invasive pneumococcal disease and pneumococcal pneumonia caused by S. pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20, 22F, 23A, 23B, 24F, 31, 33F, 35B in adults 18 years of age and older.